Electronic devices perform an increasing number functions while continually being miniaturized, becoming thus both highly portable and very useful. Such electronic devices are generally carried in a pocket of a user, but may also be installed in a wearable device, attachable, for example, to a wrist, head or arm.
Devices wearable on a human body may generally include a main body for executing a function, and a strap affixing the main body to the human body or any other suitable structures. Wearable devices may be used as standalone as subordinate devices, or may be tethered or otherwise subordinate to other electronic devices. When wearable electronic devices are used as subordinate electronic devices, a communication method using a local area network module may be implemented. Due to using wearable electronic devices, it the convenience of other non-wearable electronic devices is reduced. Accordingly, the use of wearable electronic devices is now expanding gradually.